Tissue decay in a heart typically results from a myocardial infarction (MI). Often, the decay results in chronic heart degradation and ultimate failure, as the damaged portion is unable to be restored. The deterioration is especially acute when the damage occurs to the left ventricle, which functions at a high pressure during systolic contractions to pump the blood received from the left atrium and the mitral valve, through the aortic valve and into the aorta for distribution throughout the body. The damaged tissue, operating under high pressures, eventually fails. Even without a failure, the heart is unable to function at a performance level prior to the MI, resulting in less circulation and lower blood oxygen levels.
Although cutting edge, critical care technology has been applied in the treatment and restoration of the cardiac tissues after an MI, the typical procedures are traumatic to many patients and sometimes result in mortality. Less tissue decay can result from immediate and efficient cardiac or combined cardiac and pulmonary support, but the current technology is lacking in both aspects. Current technology, including a left ventricle assist device (LVAD), extracorporeal membrane oxygenation (ECMO), and cardiopulmonary support (CPS), is either less efficient or too complicated and traumatic to already impaired anatomical systems.
Veno-Arterial (V-A) ECMO with peripheral arterial venous access using percutaneous cannulae has been available for cardiopulmonary support for several decades. Typically, a cannula is inserted into a vena cava, blood is routed through the cannula to an ECMO system for oxygenation, and the blood is returned to an artery. The multiple insertions causes trauma, can result in bleeding especially by the return path to the arterial system, and the flow rates are limited by high resistance. ECMO is also time limited, generally to less than four weeks, and has been shown to induce damage to the red blood cell (RBC). Further, ECMO does not unload the left ventricle, resulting in contractions and continued stress on the cardiac tissues. Thus, the left ventricle is unable to relax to allow at least partial healing of the muscle tissues by, for example, new growth.
LVAD systems have been used for longer-term, left ventricular support and reduced damage to the RBC. The LVAD removes blood flowing into the left ventricle, so that the left ventricle contracts at a significantly lower pressure in a more relaxed state. The blood flows to the LVAD pump and is pumped back into the aorta at an increased pressure to reduce the load on the left ventricle. However, current technology typically requires LVAD systems to be inserted into both the left ventricle to remove the blood and then returned to the aorta by a separate anastomosis of another cannula. The outlet cannula anastomosed to the aorta can especially cause complications because of the no-flow segment of the aorta root below the anastomosis, and has the possibility of clotting, thrombosis, and strokes.
Some efforts have resulted in a pump routed to the left ventricle by inserting a cable attached to an impeller into a location below the iliac artery and routing the impeller back up into the aorta, back through the aortic valve and into the left ventricle. The motor is typically located external to the body or at least the artery. The motor rotates the cable, which in turn rotates the impeller to supplement the pumping of the left ventricle. The cable, the arterial insertion, and the impeller can cause physical damage and thrombosis.
An insertion from the apex of the heart directly to the aorta was proposed about three decades ago, but the complexities of insertion and advancement to the aorta proved to be unfeasible in practice and thus did not enable the concept. Further, the cannula was not able to penetrate the chest wall and subsequently connect to a paracorporeal blood pump and oxygenator.
Even if the above procedures result in no adverse consequences, they are often performed at a subsequent time, when damage to the heart has largely occurred, due to their complexity. Further, the procedures are expensive and unavailable to many persons in need. The prognosis for healing after an MI can be greatly affected by the efficiency and availability of providing rapid assistance to the heart to encourage its healing and to provide oxygenation and circulation to supply blood to the anatomy.
Therefore, there remains a need for a simple, relatively easily accessible system and method for rapid provision of assistive devices for cardiac and/or pulmonary support.